Constant force shock absorber



Jan. 3, 1967 D. ROBERTSON 3,295,846

CONSTANT FORCE SHOCK ABSORBER Filed April 25, 1965 form mo ab/e Afmosphenc pressure Base INVENTOR Kenn efh D Roberfsorz a. 7, 59 M ATTORNEYS.

United States Patent Ofifice 3,295,846 Patented Jan. 3, 1967 3,295,846 CONSTANT FURCE SHOCK ABSORBER Kenneth D. Robertson, 20 Sumner St, Canton, Mass. 02021 Filed Apr. 23,1965, Ser. No. 450,556 3 Claims. (Cl. 267-1) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a shock absorber which exerts a constant force against a load. The invention features simplicity and low-cost construction with a minimum of movable or wearable parts.

The single figure is a cross section through the apparatus.

A supporting framework 1 rests on base 2 and has a flexible or yieldable collar 3 thereon to limit movement of platform 4, mass 5 and rod 6 in a downward direction. Movable wall 7 is connected to fixed wall 8 by bellows 9 to form an enclosed chamber. A hole 10 is provided in support 1 to allow unrestricted passage of air at atmospheric pressure into and out of the area beneath movable wall 7.

A high vacuum is induced in chamber 11 by suitable means and limitless air under atmospheric pressure is admitted below movable wall 7 through hole 10. The result is a constant upward force through wall 7, rod 6 and platform 4.

From the foregoing it is seen that a substantially constant pressure is' exerted below movable wall 7 while a substantially constant negative pressure is exerted above movable wall 7. The result is a substantially constant upward force on platform 4 produced by the simple, inexpensive apparatus described.

I claim:

1. Constant force-exerting apparatus comprising a sealed chamber, one side of said chamber comprising a movable wall, force-transmitting means connected to said movable wall to transmit force exerted by said movable wall, a high vacuum in said chamber creating a negative pressure on one side of said movable wall and atmospheric pressure applied freely to the opposite side of said movable wall to thereby exert a substantially constant force against said movable wall.

2. Apparatus as in claim 1 wherein said chamber comprises a fixed wall connected to said movable wall through a bellows so that said movable wall may move relative to said fixed wall.

3. Apparatus as in claim 2 wherein the force-transmitting means connected to said movable wall comprises a rigid member projecting through said fixed wall.

No references cited.

ARTHUR L. LA POINT, Primary Examiner.

R. M. WOHLFARTH, Assistant Examiner. 

1. CONSTANT FORCE-EXERTING APPARATUS COMPRISING A SEALED CHAMBER, ONE SIDE OF SAID CHAMBER COMPRISING A MOVABLE WALL, FORCE-TRANSMITTING MEANS CONNECTED TO SAID MOVABLE WALL TO TRANSMIT FORCE EXERTED BY SAID MOVABLE WALL, A HIGH VACUUM IN SAID CHAMBER CREATING A NEGATIVE PRESSURE ON ONE SIDE OF SAID MOVABLE WALL AND ATMOSPHERIC PRESSURE APPLIED FREELY TO THE OPPOSITE SIDE OF SAID MOVABLE WALL TO THEREBY EXERT A SUBSTANTIALLY CONSTANT FORCE AGAINST SAID MOVABLE WALL. 